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Various methods for evaluating bone mineral in appendicular, and axial bone or in the whole skeleton have recently become available. As bone mineral is one of the major determinants of bone strength, its exact measurement should be useful for the diagnosis of osteoporosis, as well as for the prediction of fracture risk and monitoring of therapeutical response. The aims of this paper are to review the fundamental performance of bone mineral measurements, the improvements in DXA systems, and the progress in site-specific bone mineral instruments for the radius and calcaneus used in Japan, and to introduce diagnostic criteria for primary osteoporosis, and report on annual rates of bone loss in Japanese females.

The purpose of this study was to determine the best bed overlaps in PET/CT 3D acquisition to reconstruct a transverse image with uniform quality not depending on axial slice position. First, the value of the image contrast ratio, non-uniformity (NU) value, and coefficient of variation (COV) were examined in the image of a cylindrical phantom at each slice position. The image-contrast ratio was almost constant in all slice images, and the NU value and COV were also constant in the slice images up to 13 and 19 slices from the center, respectively, but these values increased with closeness to the edge of the detector. Secondly, COV and image contrast ratios at different sizes of (18)F-FDG concentration (phi 19 mm, phi 16 mm, phi 13 mm, phi 10 mm) were examined in the case of overlapping the bed frame with 11, 15, and 21 slices in acquiring data in 3D mode. In 21 and 15 slices overlapping in acquisition, the image contrast ratios for all concentrations were greater than 0.13, which was the threshold image contrast ratio needed to identify FDG concentration from the background image with naked eye scanning under our conditions. However, in 11 slices with overlapping acquisition, the image-contrast ratio for a phi 10 mm concentration were close to or less than 0.13 in the all slice images. As a result, 15 overlapping slices was a reasonable minimum number of slices to identify a phi 10 mm (18)F-FDG concentration while maintaining the image quality in PET/CT 3D acquisition in our institution.

Squamous cell carcinoma (scc) is the most frequently type of oral cancer, but no reliable specific tumor markers of scc have been obtained. In this paper, the authors applied measurement of squamous cell carcinoma related antigen (scc antigen), a useful tumor marker of scc of the uterine cervix, to oral cancer patients and evaluated the clinical values of scc assay in diagnosis, follow-up and prognosis.The subjects were 29 cases of oral cancer and 23 cases of benign oral disease. The oral cancer cases included 12 cases of tongue cancer, 5 of buccal cancer, 4 of gingival cancer, 2 of cancer of the oral floor, 2 of cancer of the maxillary sinus and 4 cases of other cancers. Twenty one of these cases (about 72%) were histologically scc.Serum scc antigen levels were determined by the RIA KIT employing 125 I-labelled scc antigen as tracer. The cut off level was set as 2.3ng/ml.The following results were obtained.1) The subjects with oral cancer exhibited a higher scc antigen level than those of patients with non-bearing oral cancer or those of cases with benign oral diseases.2) The positive rate of the subjects with oral cancer was relatively high and 44% were at a level over 2.3ng/ml. Particularly in scc, 60% were at a level over 2.3ng/ml. Among 16 subjects with non-bearing oral cancer, on the other hand, only one subject showed positive. All subjects with benign oral disease were within normal range.3) As to the regions of oral cancer, tongue cancer and cancer of the oral floor showed relatively high scc antigen levels.4) There was no relationship between stages and scc antigen levels.5) Post-treatment scc antigen levels tended to decrease to within normal range in cases where the disease followed a good course, while they tended to increase in those that followed a poor course.6) The measurement of scc antigen levels appears to be especially useful for diagnosis, follw-up and evaluating prognosis in oral squamous cell carcinoma.

The usefulness of bone scintigraphy using 99m-Tc-labeled phosphorous compounds was evaluated in 134 of 234 patients with cancers of the head and neck who were treated between June 1975 and March 1985.The overall positive rate in bone scintigraphy was 49%, but the true-positive rate was 25%. Distant bone metastases were found in 18% of the patients. Fifty-five per cent in the patients with true-positive bone scintigraphy had positive x-ray findings. The most common sites of distant bone metastases in head and neck cancers were the rib and the thoracic vertebrae. The rate of distant metastases increased with the T-classification. No relation was observed between bone scintigraphy and serum alkaline phosphatase activity.In conclusion, bone scintigraphy with 99m-Tc-diphosphonate was found to be very useful in detecting early bone metastases.

A newly developed dual photon absorptiometry system (DCS-600, ALOKA Co., LTD.) using two monochromatic X-rays for the determination of bone mineral in the peripheral bone was fundamentally studied, in comparison to single photon absorptiometry system (SPA). The accuracy and precision in DCS-600 were equal to or better than SPA system. Furthermore, in DCS-600 the forearm could be imaged, and the manipulation was easy. Thus DCS-600 was found to be a good instrument as a quantifying system of bone mass.